scholarly journals Bonding Behavior of Conventional PMMA towards Industrial CAD/CAM PMMA and Artificial Resin Teeth for Complete Denture Manufacturing in a Digital Workflow

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3822
Author(s):  
Dominik Klaiber ◽  
Sebastian Spintzyk ◽  
Juergen Geis-Gerstorfer ◽  
Andrea Klink ◽  
Alexey Unkovskiy ◽  
...  

When applying a digital workflow, custom artificial resin teeth have to be integrated into a milled complete denture base, using polymethylmethacrylate (PMMA) applied with a powder–liquid technique. Debonding of denture teeth from dentures is reported to be a frequent complication. No evidence is provided as to which method of surface treatment may enhance the bonding strength. The bonding strength between artificial teeth and PMMA (Group A, n = 60), as well as between the PMMA and industrial PMMA (Group B, n = 60), was investigated following no treatment, monomer application, sandblasting, oxygen plasma, and nitrogen plasma treatment. Surface-roughness values and SEM images were obtained for each group. Shear bond strength (SBS) and fracture mode were analyzed after thermocycling. Within Group A, statistically significant higher SBS was found for all surface treatments, except for nitrogen plasma. In Group B, only nitrogen plasma showed a statistically lower SBS compared to the reference group which was equivalent to all surface treatments. Conclusions: Within the limitations of the present study, the monomer application can be proposed as the most effective surface-treatment method to bond custom artificial teeth into a milled PMMA denture base, whereas nitrogen plasma impairs the bonding strength.

2018 ◽  
Vol 1 (1) ◽  
pp. 1-5
Author(s):  
Binita Pathak ◽  
S. Mathema ◽  
R. Sharma

Introduction: Polymethyl methacrylate as denture base material is not ideal in many aspects. The primary problem is its poor strength characteristics, including low impact and flexural strength. The fatigue failure occurs when the denture base deforms repeatedly through occlusal forces, hence dentures tend to break during usage in due course of time. The aim of this study was to measure and compare the flexural strength of heat cure Polymethyl methacrylate denture base resin with and without reinforcement of polyethylene fiber. Method: A total of 52 specimens (maxillary complete denture) were divided into 2 groups (n=26); Group A(Control): Dentures without reinforcement, Group B: Dentures reinforced with Polyethylene fiber. All specimens were subjected to three-point bending test in UTM. A flexural load was applied to each maxillary complete denture at a speed of 5mm/min until fracture and the flexural load required to break specimen was recorded. Results: The mean values and standard deviation of each test specimen group was calculated and statistical analysis of obtained values was done using ANOVA. Mean flexural strength for Group A was 142.66±29.95 MPa and Group B was 218.88±29.96 MPa. Group comparison showed a statistically significant difference (p<0.001) between group A and B. This suggested that flexural strength for specimens reinforced with Polyethylene fibers was significantly higher than specimens without reinforcement. Conclusion: Reinforcement of heat cure polymethyl methacylate denture base resin with polyethylene fiber resulted in significant increase in flexural strength.  


2019 ◽  
Vol 13 (3) ◽  
pp. 200-207
Author(s):  
Vikram M. Belkhode ◽  
Sharayu V. Nimonkar ◽  
S. R. Godbole ◽  
Pranali Nimonkar ◽  
Seema Sathe ◽  
...  

Background. Dental porcelain has excellent esthetics in combination with biocompatibility and is one of the most commonly used restorative materials. Its low tensile strength remains a major drawback. The porcelain-fused-to-metal restorations have been introduced to increase the fracture resistance of dental porcelain. The aim of this study was to evaluate the effect of different surface treatments on the bond strength of a non-precious alloy to ceramic. Methods. The present cross-sectional observational study was conducted with forty samples of cobalt‒chromium that were fabricated with porcelain interposed between the two metal test pieces. The metal was subjected to combinations of different surface treatments. The samples group A (n=10) were not subjected to any surface treatments. Group B samples underwent sandblasting and surface grinding. Group C samples were subjected to sandblasting, surface grinding and degassing; and group D samples underwent sandblasting, surface grinding, ultrasonic cleaning and degassing. The tensile bond strength was measured in a universal testing machine, and a scanning electron microscope (SEM) was used to obtain images of the samples after surface treatment to determine the surface irregularities and after the debonding of the samples for the type of the bond failure. ANOVA was used for the statistical analysis. Results. The results showed significant variations in the tensile bond strength between the four groups (F=251.05, P=0.000). The SEM images of group A showed no surface irregularities; group C samples exhibited surface irregularities more than those in group B. Group D had the highest surface irregularities. SEM evaluations showed a statistically significant difference in the type of bond failure (P<0.001). Conclusion. Based on the results of this study, it can be concluded that the surface treatments on the metal increased the bond strength of the metal‒ceramic interface significantly. A combination of sandblasting, surface grinding and ultrasonic cleaning, followed by degassing, resulted in the highest tensile bond strength.


2020 ◽  
Vol 32 (1) ◽  
pp. 66
Author(s):  
Siti Wahyuni ◽  
Chairunnisa Ricca

Pendahuluan: Nilon termoplastik merupakan basis gigi tiruan yang banyak diminati oleh para dokter gigi karena memiliki beberapa keuntungan dibandingkan bahan basis gigi tiruan resin akrilik. Diantara jenis nilon termoplastik yang sering dijadikan basis gigi tiruan adalah poliamida 6 dan poliamida mikrokristalin. Poliamida Mikrokristalin merupakan poliamida generasi baru yang dibuat untuk menanggulangi kelemahan pada poliamida sebelumnya. Tujuan penelitian ini adalah menganalisis pengaruh minuman teh pada pengguna gigi tiruan nilon termoplastik terhadap penyerapan air dan stabilitas warna. Metode: Jenis penelitian ini adalah experimental laboratoris. Jumlah sampel terdiri dari 40 dengan  ukuran diameter 15 mm ± 1 mm dan ketebalan 0.5 mm ± 0,1 mm (ISO 4049) dan terbagi menjadi 4 kelompok (kelompok A poliamida 6 dan kelompok B poliamida mikrokristalin untuk penyerapan air serta kelompok C poliamida 6 dan kelompok D poliamida mikrokristalin untuk uji stabilitas warna). Semua sampel direndam dalam larutan teh selama 7 hari. Data dianalisis dengan uji T Independen. Gambaran mikroskopis sampel diuji dengan SEM Hasil: Berdasarkan uji T Independen hasil menunjukkan perbedaan yang signifikan diantara kelompok A dan B, C dan D.  Uji T independen menunjukkan perbedaan yang signifikan diantara kelompok A dan B, C dan D (p=0,0001, p<0,05) Simpulan: Terdapat pengaruh minuman teh pada pengguna gigi tiruan nilon termoplastik. Poliamida Mikrokristalin memiliki penyerapan air yang lebih sedikit dan stabilitas warna yang lebih baik dibandingkan Poliamida 6.Kata kunci: Nilon termoplastik, poliamida 6, poliamida mikrokristalin, penyerapan air, stabilitas warna, SEM. ABSTRACTIntroduction: Thermoplastic nylon is a denture base mostly demanded by dentists due to its several advantages over acrylic resin denture base material. Among the types of thermoplastic nylon that are often used as denture bases are polyamide 6 and microcrystalline polyamide. Microcrystalline polyamide is the new generation of polyamides created to overcome the weaknesses of previous polyamides. The purpose of this study was to analyse the effect of tea on thermoplastic nylon denture wearers on water absorption and colour stability. Methods: This research was experimental laboratory research on 40 samples with a diameter of 15 mm ± 1 mm, and a thickness of 0.5 mm ± 0.1 mm (ISO 4049), divided into four groups (Group A was the polyamide 6; Group B was the microcrystalline polyamide on the water absorption; Group C was polyamide 6; and Group D was microcrystalline polyamide on the colour stability). All samples were immersed in the tea solutions for 7 days. Data were analysed with independent t-test. The microscopic structure was analysed using the scanning electron microscope (SEM). Results: The results showed significant differences between group A, B, C, and D. The independent t-test also showed significant differences between group A, B, C, and D (p = 0.000; p < 0.05). Conclusion: There is an effect of tea on the thermoplastic nylon denture wearers. Microcrystalline polyamides have less water absorption and better colour stability than Polyamide 6.Keywords:  Polyamide 6, thermoplastic nylon, microcrystalline polyamide, water absorption, colour stability, SEM.


2015 ◽  
Vol 19 (3) ◽  
pp. 128-131
Author(s):  
Ender Akan ◽  
Ibrahim Talha Meşe

SummaryMonolithic zirconia restorations offer superior mechanic properties and improve indication of non-metallic restorations. Monolithic restorations eliminate bonding and chipping problems mostly seen in zirconia restorations. However, optical properties are insufficient. Colouring or staining is offer possibility to mask the opaque view of restoration. Polishing and glazing are also surface treatment methods for monolithic zirconia.In this study effect of surface treatment methods on final view of zirconia were evaluated. For this purpose 30 monolithic zirconia samples (inCoris TZI, Sirona, Bensheim, Germany) were prepared. The samples were divided into 3 groups: In group A (n=10), glazing was performed using Vita Glaze (Vita Zahnfabrik, Bad Saeckingen, Germany); In group B (n=10), polishing was performed by using Soflex polishing system (3M-ESPE, Neuss, Germany); in Group C (n=10), polishing and glazing were performed. Before and after the applied the surface treatment methods, colour measurements were performed with a spectrophotometer (Vita EasyShade Advanced, Vita Zahnfabrik, Bad Saeckingen, Germany). Data were analysed using paired sample t-test at the p≤0.05 level and one-way analysis of variance (ANOVA) combined with Tukey’s multiple comparison tests.In all groups there were alterations in colour values; however, ΔE< 3.7 and the colour changes were undetectable.


2015 ◽  
Vol 41 (5) ◽  
pp. e183-e188 ◽  
Author(s):  
Aswini Kumar K ◽  
Vinaya Bhatt ◽  
Manilal Balakrishnan ◽  
Mohamed Hashem ◽  
Sajith Vellappally ◽  
...  

This study compared the surface topography, hydrophilicity, and bioactivity of titanium implants after 3 different surface treatments (sandblasting and acid etching, modified sandblasting and acid etching, and thermal oxidation) with those of machined implants. One hundred indigenously manufactured threaded titanium implants were subjected to 3 methods of surface treatment. The surface roughness of the nontreated (Group A) and treated samples (Groups B through D) was evaluated with a scanning electron microscope (SEM) and profilometer. The wettability was visually examined using a colored dye solution. The calcium ions attached to the implant surface after immersing in simulated body fluid (SBF) were assessed on days 1, 2, and 7 with an atomic electron spectroscope. The data were analyzed statistically. The SBF test allowed the precipitation of a calcium phosphate layer on all surface-treated samples, as evidenced in the SEM analysis. A significantly higher amount of calcium ions and increased wettability were achieved in the thermally oxidized samples. The mean roughness was significantly lower in Group A (0.85 ± 0.07) compared to Group B (1.35 ± 0.17), Group C (1.40 ± 0.14), and Group D (1.36 ± 0.18). The observations from this in vitro study indicated that surface treatment of titanium improved the bioactivity. Moreover, results identified the implants that were sandblasted, acid etched, and then oxidized attracted more calcium ions.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hasan Skienhe ◽  
Roland Habchi ◽  
Hani Ounsi ◽  
Marco Ferrari ◽  
Ziad Salameh

This study evaluated the effect of air abrasion before and after sintering with different particle type, shape, and size on the surface morphology, monoclinic phase transformation, and bond strength between resin cement and zirconia surface using primer containing silane and MDP. Airborne particle abrasion (APA) was performed on zirconia before and after sintering with different particle shape and size (50 μm Al2O3 and 25 μm silica powder). 120 square shaped presintered zirconia samples (Amann Girrbach) were prepared (3 mm height × 10 mm width × 10 mm length) and polished with grit papers #800, 1000, 1200, 1500, and 2000. Samples were divided into 6 groups according to surface treatment—group A: (control) no surface treatment; group B: APA 50 μm Al2O3 before sintering (BS); group C: APA 50 μm Al2O3 after sintering (AS); group D: APA25 μm silica powder (BS); group E: APA25 μm silica powder (AS) at a pressure of 3.5 bar; and group F: APA 25 μm silica powder (AS) at a pressure of 4 bar. Samples were analyzed using XRD, AFM, and SEM. The samples were submitted to shear bond strength (SBS) test. A dual cure resin cement (RelyX Ultimate) and primer (Scotchbond Universal) were used. Data were analyzed with ANOVA and Tukey test (α≥0.05). APA in group B significantly increased the surface roughness when compared to all other groups. A significant monoclinic phase transformation (t-m) value was observed in groups C and F and a reverse transformation occurred in presintered groups. The SBS value of group A was 11.58±1.43 and the highest significant shear bond strength value was for groups B (15.86±1.92) and C (17.59±2.21 MPa) with no significant difference between them. Conclusions. The use of APA 50 μm Al2O3 before sintering and the application of primer containing MDP seem to be valuable methods for durable bonding with zirconia. The use of APA 50 μm Al2O3 after sintering induced the highest (t-m) phase transformation.


2021 ◽  
Vol 10 (28) ◽  
pp. 2051-2055
Author(s):  
Puja Harie Priya M.S ◽  
Brintha Jei J. ◽  
Murugesan Krishnan ◽  
Muthukumar Balasubramanium

BACKGROUND Polymethyl-methacrylate (PMMA) resin is the most commonly used denture base material which satisfies colour stability, aesthetic demands, accurate fit, affordable cost, and ease in manipulation. The common disadvantages are incomplete flow, impact strength, transverse strength and fatigue resistance. The fracture of denture base is mainly due to flexural fatigue failure which can be minimised by reinforcing with various artificial and natural fibres. There are very few studies which have incorporated natural fibres to enhance the strength of PMMA resin. So, in this study both natural and artificial fibres were used to enhance the property and find the best fibres to strengthen the denture base. METHODS A total of 80 samples were prepared using a standardized stainless steel metal die and these samples were grouped into Group A as control group, Group B PMMA samples reinforced with raw teak wood fibres, Group C reinforced with alkali treated teak wood fibres, Group D reinforced with heat treated teak wood fibres and Group E samples were reinforced with Ultra-High molecular weight (UHMW) polyethylene fibres and processing was carried out by conventional method. The flexural strength of each sample was calculated. RESULTS The mean flexural strength of Group A, Group B, Group C, Group D and Group E were 82.338, 58.680, 62.259, 105.878, 90.2263 respectively with a P value of 0.001. Group D samples showed a P value < 0.001 which was statistically significant when compared to other groups. The obtained values were statistically analysed by oneway ANOVA and Tukey’s HSD test using statistical software SPSS 17. CONCLUSIONS This in-vitro study infers that the samples of Group D incorporated with heat treated teak fibres had shown increased flexural strength, which could be a good replacement for various synthetic and natural fibres to enhance the strength of denture base resins. KEY WORDS Teakwood Fibres, Heat Treatment, Alkali Treatment, Sandwich Technique, Polyethylene Fibres


2012 ◽  
Vol 37 (3) ◽  
pp. 299-305 ◽  
Author(s):  
S Jafarpour ◽  
W El-Badrawy ◽  
HS Jazi ◽  
D McComb

SUMMARY Objective The objective of this study was to investigate, by simulation, the effect of conventional composite resin insertion techniques on cuspal deflection using bonded typodont artificial teeth. The deflection produced by a new low-shrinkage composite was also determined. Materials and Methods Sixty standardized MOD preparations on ivorine maxillary premolars were prepared: group A at 4 mm depth and group B at 6 mm depth. Each group was further subdivided according to composite insertion technique (n=6), as follows: 1) bulk insertion, 2) horizontal increments, 3) tangential increments, and 4) a modified tangential technique. Preparations were microetched, acid-cleaned, and bonded with adhesive resin to provide micromechanical attachment before restoration with a conventional composite (Spectrum TPH3, Dentsply). Two additional subgroups at 4 mm and 6 mm depth (n=6) were restored in bulk using low-shrinkage composite (Filtek LS, 3M/ESPE). All groups received the same total photo-polymerization time. Cuspal deflection was measured during the restorative procedure using two Linear Variable Differential Transformers attached to a data acquisition system. Results The average cuspal deflections for group A were 1) 40.17 ± 1.18 μm, 2) 25.80 ± 4.98 μm, 3) 28.27 ± 5.12 μm, and 4) 27.33 ± 2.42 μm. The deflections in group B were 1) 38.82 ± 3.64 μm, 2) 50.39 ± 9.17 μm, 3) 55.62 ± 8.16 μm, and 4) 49.61 ± 8.01 μm. Cuspal flexure for the low-shrinkage composite was 11.14 ± 1.67 μm (group A: 4 mm depth) and 16.53 ± 2.79 μm (group B: 6 mm depth). Conclusions All insertion techniques using conventional composite caused cuspal deformation. In general, deeper preparations showed increased cuspal deflection—except in the case of bulk insertion, which was likely affected by decreased depth of cure. Cuspal movement using low-shrinkage composite was significantly reduced.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Ghassan Abdul-Hamid Naji

The process of repairing the fractured nylon denture bases and addition of acrylic teeth to the previously worn nylon denture bases has not been widely studied. This study aims to assess the transverse strength of nylon denture bases repaired by various resin materials, different curing techniques, and types of surface treatments. Materials and Methods. One hundred fifty thermoplastic nylon denture base samples were fabricated using plastic patterns measuring 65 × 10 × 2.5 mm (length, width, and thickness, respectively). These samples were then divided into three equal groups. Fifty samples were repaired by microwave heat-polymerization, fifty samples were repaired using the Ivomate autopolymerization, and the other fifty were repaired using light-polymerized acrylic resin. Each of these three groups was further divided into five subgroups of ten samples based on the type of surface treatment. The samples in the control group did not undergo any surface treatment, and the other four groups were chemically surface treated with monomer, acetone, ethyl acetate, and isopropanol, respectively. A three-point bending test was used to calculate the transverse strength values of the samples. Fourier transform infrared (FTIR) analysis was conducted to determine the component of functional groups between the polyamide nylon base and poly(methyl-methacrylate) PMMA repair materials. A polarizing microscope was utilized to investigate the mode of failure at the fracture surfaces. Results. The collected data were analyzed with one-way ANOVA and Sidak’s multiple comparison test to show the differences among different groups. For surface treatments, the highest transverse strength values were obtained by monomer-treated samples (18.29 N/mm2); however, the lowest values were obtained in non-surface treated samples (5.58 N/mm2). While for repair techniques, the highest transverse strength values were obtained by microwave processing, followed by Ivomate and then the light-cured polymerization. The means were found to be significant (p<0.001). FTIR analysis shows the presence of hydrogen bonding which is due to the ester and amid groups which enhance the bond strength of the surface-treated samples. The interface of the polarizing microscope images revealed a cohesive fracture within repair materials rather than the adhesive nature. Conclusion. The microwave-polymerized resin was considered as the most effective repair technique along with monomer chemical etchant which creates a tight adhesion between PMMA and nylon denture base in comparison to other groups.


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